Tire deflation signal



sept. 2o, 1932.

H. T. LAMBERT I TIRE DELATION ASIGNAL Filed Oct. 5, 1931 FIG. 2.

INVENTOR HJWARD T. LAW/17T ZM ATTORNEY Patented Sept. 20, 1932 UNITEDSTATES i 1,878,4.111jjV ,PATENT` oFFici:A

HOWARD T. LAMBERT, F JOHNSTOWN, IIEE1\TIN'SYITA1\TIA;Y4 IRA` GILBERTLAMBERT,

EXECUTOR OF SAIDy HOWARD T. LAMBERT, DECEASED TIRE DEFLATION SIGNAL.Animation mea'october 5, 1931. serial No. 566,830.

This invention relates to tire deflation signals and more particularlyto an audible defiation signal combined with Vthe check valve of theinner tube. The principal object of the invention is to operate thesignal when the tire becomes underinflated.

Another object is todiscontinue the operation of the signal after apredetermined interval to prevent the complete deflation ofthe tire. v

Another object is to provide means for the adjustment of the signal tooperation at varying pressures.

A further object is to minimize the cost of production of the signal byutilizing a pair of conventional tire check valves for operating thesignal. Other objects and advantages appear as the descriptionprogresses. v

In the specification and the accompanying drawing the invention isdisclosed lin its preferred form. It is to be understood, however, thatit is not limited to this form because it may be embodied in other formswithout departing from the spirit of the invention as define-d in theclaims following the description.

In the accompanying one sheet of drawing:

Fig. 1 is a side elevation view of a tire deflation signal constructedin accordance with this invention.

2 is a vertical section of the saine.

In detail the construction illustrated in the drawing, referring moreparticularly to Fig. 2, the tubular valve stem 1 has its lower end fixedin the conventional inner .tube in the usual manner. The upper end ofthe valve stem is internally threaded at 2 for ashort distance toreceive the hollow bushing 3. The bushing is provided with twoupstanding lugs 4c which are adapted to be engaged by a suitabletoolfo-r screwing in .the bushing until it seats at thelower. end of thethread 2.

lThe neck 5 of the bushing extends downwardly therefrom and terminatesin the annular valve seat 6. The resilient baffle 7 snugly engages theneck 5 and impinges on 50 the walls ofthe central opening ofthe valvestem to divert the ffull air pressure of the tire from the threads ofthe bushing v3.

The valveplunger 8 extends through the hollow bushing 3 and has theenlarged head 9 at its upper end to'prevent the plunger falling throughthe bushing 3 when the valve assembly is removedv fromthe stem 1,.v Thevalve 10 is fixed on the plunger 8 and has the resilient washerlladapted to cooperate with the valve seat 6. The rosette guide 12 restson the annular shoulder 11 yformed in the central passage of the stem land has the interspaced openingsl to permit the escape of airtherethrough. The lower end of the valve plunger passes through thisguide' and is enlarged by beingflattened at 14 to hold the guide-inplace when the valve assembly is removed.

The spring 15 encircles the valve plunger and expands betweentheguide12jand the valve 10 to urgethevalve upward into engagement withthe seat 6.. lThe air pressure of the tire working against the backofthe valve assists the spring 15 in maintaining lthe valve normallyseated. c A

To inflate the-tire, compressed air is applied to the upperend of thecentral opening ofthe valve stem. The pressure of this air overcomes thetension of the spring 15 and unseats the valve 10. rAir then flowsthrough the bushing 3, past the valve 10 Aand through the openings inthe'guide 12 into the inner tube, thus iniiatingthe tire. f

`When it is desired to deflate the tire, the plunger 8 is manuallypressed downward to unseat the valve 10, permittingthe air to escape.

The construction just described is the conventional air check valve soldunder the trade nameuof Schrader. The-details of this construction willvary with other makes but with all of which the present invention may becombined byl modifications obvious to those skilled inthe art. j

The upper end of the stem 1 is, as usual, reduced in diameter andthreaded to receive the conventional valve cap. To apply this inventionto the tire, the valve cap :is -'re` moved and the adjustable lock nut16 and internally threaded bushing 17 are screwedv on 100 the valvestem. The lower end of the bushing 17 is formed into a hexagon tofacilitate screwing it on the end of the valve stem.

The tubular body 18 has its lower end reduced in diameter and threadedto enter the bushing 17. The interior of the body'18 is internallythreaded at 19 at its lower end for a limited distance.

A second valve assembly similar to the Schrader valve previouslydescribed has the bushing 8 with the depending lugs 4 and screwed intothe threads 19 unt-il the bushing seats at the end of the thread. Theneck has the baliie 7 thereon and terminates in the annular valve seat6.y

The valvelO is fixed on the plunger -8 and is adapted to Acooperate withthe valve seat 6. The spring 15 encirclesthe plunger 8 and expandsbetween the valve 10 and the rosette 'guide 12 urging the valvedownwardtoward its seatV and forcing the guide upward against the lower end ofthe screw 20. This-screw is threaded through the center of the flangedlcap 21 which is internally threaded at 22 to engage the threaded upperend of the body 18. The lower end of the screw 20 is lcentrally boredtopass the end 14 of the plunger 8. The pipe whistle 28 is fixed 'in thelower side'of the 'flanged fcap -21 and depends therefromparallel withthe body 18. The upper end -of the whistle is closed by the vplug 2,4;having the peripheral slot 25 therein. This slo'i'J ycommunicates withkkthe interiorof the tubularbody 18 through -the'passage l26 and isadaptedy'to direct Sa blast-'of escaping air against the sharpened beveledge 27 ycut in the side of the tube-`28.. This "produces an audiblewhistling signal of sufficient Yvolume to be heard by the operator of-fth'e vehicle upon which 'it lis used. i The whistle23 must be offairly accurate manu-facture to-enable it to operate with y'a widerangef'of vair pressures. p

The lower end 'of the tube 23 iis lclosed by the plug 4screw V28threaded therein. This screw can Abe periodically removed to ycleanaccumulations of 'mud :and dust from 'the whistle. f f

'The lower end yof 'the Vplunger 8 is provided with the enlarged head9"'which is adapted to impinge on vtheghead 9, causing the 'plungers 8 8tooperateasa unit.

When the vtire is inflated gto-Yits correct` pressure, the airpressure'ofthe tire,'imping ing onthe valve 8, maint'ains'thevalveseated against the tensiony ofthespring y15 which exerts a i downwardfpressure 'on the plunger 8 tending to unseat the Valve @10. Thisprevents the Vspring 15 from llowering the plunger 8 sufficient'toclose'the 'valve 10. Thus this valve remains open asshown in Fig. 2. I

When L'the tire Abecomes underinflated `vto a v few -pounds under itscorrect pressure,'the

This unseats the valve.

to exert a pressure equal to the tension of the spring 15, plus thepressure of theV comvpressed air in the tire.

The exact point at which the spring 15 counter-balances the combinedtension of the spring 15 and the air pressure of the tire, can beregulated by adjusting the screw 20 to vary the tension of the spring15. Thus, the device can be adjusted to operate when the pressure in thetire falls to .any prede termined poundage.

When the valve 10 is unseated by the counterbalancing of the springs 1515, due to the vloss of airpressure in the tire, a small quantity ofcompressed air escapes past the valves 10'-10 and flows up the body 18and through the restricted slot 25 to operate the whistle 23. Y

After the whistle hasbeen operating for some time, the escaping airstill further diminishes the air pressureinvthe tire.. This reduces thepressure exerted against theback of the valve 10. The yspring 15 thencom pletely overcomes the resistance of the spring 15 andfcloses thevalve 10 preventing further escape of air and discontinuingthe-operation of vthe `audible vsignal 23. This allows sucient airpressure to remainfinthe tire to prevent complete deflation. l

By adjusting the bushingv 17 and the lock nut 16 on the neck of thevalve stem 1 O,jthe distance between the 'two valve assemblies can beregulated to vary the displacement of the valve 10', as shown in dottedlines 10, when the tire is inflated to the correct @pressure. Thisregulates the interval of time required for the valve 10 to seat underthe constant gradual expansion ofthe springr15 when the signal isoperating, andl consequently determines the air pressure left in thevtire after the signalha-s ceased operating. 'Thus the device-maybeaccurately adjusted to discontinue its'operation when the air .pressureof the tire ifalls to yany desired poundage. When the lock nut is'onceproperly adjusted on the neck of. the valve '1, the bushing 17 mayberemoved andreplaced without affecting the-adjustment ofthe lock nut.

Having thus described this invention, what I-claim and desire to secureby Letters Pat'- ent is: Y 1

1. A .tire deflation signal comprising signal means, a valve adapted toreleaseair from the tire to operate said signal means, means to opensaid valve'when the air in the tire falls below a vpredeterminedpressure, and means to close said valvev when the air pressure of thetire-is further reduced.

2. A defiation signal for pneumatic tires having a check valvecomprising an audible signal operable by the release of air by saidcheck valve, and resilient means adapted to open said check valve whenthe air in the tire falls below a predetermined pressure, and Y means todiscontinue the escape of air when the pressure of the tire is furtherreduced.

3. A deflation signal for pneumatic tires comprising a check valve, anaudible signal operable by the release of air from the tire by saidcheck valve when the air in the tire falls below a predeterminedpressure, and a second valve interposed between said check valve andsaid signal and adapted to close when the air pressure in the tire isfurther reduced.

4. A tire deflation signal comprising a check Valve closing said tire,an audible signal operated by the release of air by said check valve, asecond valve interposed between said check valve and said signal, andresilient means adapted to open said check valve when the air in thetire falls below a predetermined pressure and adapted to close saidsecond valve when the air pressure is further reduced.

5. A tire deflation signal comprising a hollow stem Xed to said tire, apair of conventional tire Valves oppositely disposed to each other insaid stem, one of said valves acting as a check Valve to close saidtire, plungers fixed in said valves adapted to impinge against eachother, resilient means cooperating with one of said Valves and adaptedto open said check Valve when the air in the tire falls below apredetermined pressure and adapted to close the other Vvalve when theair pressure is further reduced, and an audible signal Xed on the end ofsaid stem and operable by the release of air therefrom.

In testimony whereof I have hereunto set my hand this 25th day ofSeptember, 1931.

HOWARD T. LAMBERT.

